Direct-lit light source apparatuses having a plurality of light-emitting diodes as a light source have become widespread lately in the field of liquid-crystal display apparatuses. In a direct-lit light source apparatus, a plurality of light emitting diodes (LEDs) are arranged in a matrix on a substrate, and a diffusing lens is for example provided over each LED for diffusing light emitted from the LED. The light diffused by the diffusing lens is further diffused by a diffusion plate, and then enters a liquid-crystal panel, for example.
In the case of the use of a diffusing lens formed by injection molding, which involves injection of resin to an injection mold through an injection port, the diffusing lens has an injection-port-shape impression on an outer circumferential section of a light exit surface thereof, and the injection-port-shape impression causes undesired light scattering.
Patent Literature 1 discloses a light flux control member (a diffusing lens) that can inhibit the above-described light scattering on an injection-port-shape impression without the need to extremely reduce a thickness of the injection port.